1. Field of the Invention
The invention relates to a vacuum interrupter.
2. Description of the Related Art
Recent studies have found that the heavy breakdown has an affinity to the high-frequency inrush current. As the contact surface is locally ablated by the high-frequency current during the close of the switch, fusion welding occurs on the contact, and the surface structure of the contact is damaged, thereby increasing the field emission coefficient β of the contact surface.
A typical vacuum interrupter generally includes a pair of movable contacts. For example, a power-off and disconnecting switch device equipped with a vacuum box includes different positions of movable contacts inside the vacuum interrupter for controlling the connection, breaking, and disconnection of the current. For another example, a high voltage vacuum switch achieves anti-high-voltage property of the vacuum interrupter by controlling a pair of the movable contacts to be disposed inside a pair of shield contacts at a full open position. Although multiple working positions of the vacuum interrupter are disposed, the current breaking function is not independent from the insulating function after the disconnection.